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United States Patent |
5,262,865
|
Herz
|
November 16, 1993
|
Virtual control apparatus for automating video editing stations
Abstract
A virtual control apparatus for emulating a video mixer through a computer,
wherein the computer can receive data and command information from its own
command input devices. The data and command information are mapped into
data in format recognizable by the CPU within the computer. The resulting
data and command are stored in the memory of the computer and/or
transferred to the video mixer for immediate video manipulation. Data
transfer between the video mixer and the computer is implemented through a
communication tool, which establishes the protocol of communication
between the computer and the video mixer. Edit decisions from the video
mixer can be transferred to and saved in the computer memory for
subsequent use. Also disclosed is a video communication tool between a
video mixer and a computer. When serial data and control signals are
transferred from the video mixer to the computer, serial data are
converted into parallel data through a state machine and control logic
unit, upon the beginning of a new frame. The parallel data are transferred
to a FIFO. Upon the end of frame the FIFO is ported to the computer. When
parallel data and control signals are transferred from the computer to the
video mixer, parallel data are stored in a FIFO. Upon an appropriate
control signal from the state machine, parallel data are converted into
serial data. The serial data are clocked to the video mixer on the rising
edge of the clock.
Inventors:
|
Herz; William (Newark, CA)
|
Assignee:
|
Sony Electronics Inc. (Park Ridge, NJ)
|
Appl. No.:
|
925321 |
Filed:
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August 4, 1992 |
Current U.S. Class: |
348/705; 348/722 |
Intern'l Class: |
H04N 005/222 |
Field of Search: |
358/181,311,903,185
|
References Cited
U.S. Patent Documents
4698664 | Oct., 1987 | Nichols | 358/185.
|
4745478 | May., 1988 | Nakagawa | 358/181.
|
Other References
Sony Edit Gear XV-Z10000, Apr. 1989.
|
Primary Examiner: Groody; James J.
Assistant Examiner: Harvey; David E.
Attorney, Agent or Firm: Blakely Sokoloff Taylor & Zafman
Parent Case Text
This is a continuation of application Ser. No. 07/715,332 filed on Jun. 14,
1991, now abandoned.
Claims
What is claimed is:
1. A virtual control apparatus for controlling at least one video mixer,
said video mixer performing edit operations on a plurality of video input
sources coupled to said video mixer, said edit operations performed in
accordance with an edit command received, said video mixer issuing video
mixer control signals indicative of timing of signals of video input
sources coupled to the video mixer, said virtual control apparatus
comprising:
computer means including memory, mass storage, and command input devices
for entering edit commands representing said edit operations to be
performed on said video input sources by said video mixer, said memory
comprising a data array comprising a plurality of data words, for storage
of a plurality of edit commands representative of edit operations entered
via the input devices, said computer means formatting and storing said
edit commands in the data array;
communication means for transferring said edit commands between said
computer means and said video mixer, said communication means comprising;
a first input means for receiving video mixer control signals and the data
array when input commands are to be executed on the video mixer,
a FIFO buffer for storing the plurality of data words of the data array
received, control signals from said video mixer,
conversion means for converting the contents of the data array located in
the FIFO buffer to serial data for output, and
control logic means coupled to the input means and conversion means for
controlling the conversion and output of the data array as serial output
data signals to said video mixer upon receipt of video mixer control
signals;
such that said serial output data signals comprising a plurality of edit
commands are received within a single transmission to cause said video
mixer to invoke said edit operations during a single frame.
2. The virtual control apparatus as defined by claim 1, wherein said video
mixer control signals comprise BEGIN signals, INTERVAL signals, and CLOCK
signals, such that each of said BEGIN signals triggers a frame in said
video mixer, and said CLOCK signals synchronize each bit of said data
array output as serial output data.
3. The virtual control apparatus defined by claim 2, wherein said control
logic means controls the conversion means to convert a data word into
serial output data if one of said INTERVAL signals received after one of
said INTERVAL signals is synchronously received with one of said BEGIN
signals.
4. The virtual control apparatus defined by claim 3, wherein said
communication means transmits said serial output data signals to said
video mixer synchronous with the rising edge of said CLOCK signals.
5. The virtual control apparatus defined by claim 1, wherein said
communication means further receives serial input data signals from said
video mixer, converts said serial input data signals into said data array,
and transfers said data array to said computer means as feedback to the
edit operations performed.
6. The virtual control apparatus defined by claim 5 wherein said
communication means further comprises:
a second input means coupled to receive said serial input data signals from
said video mixer;
control logic means coupled to receive said video mixer control signals,
said control logic means generating a first signal upon receipt of a first
video mixer control signal indicative that a word of serial data signals
has been received and a second video mixer control signal indicative that
a number of data words corresponding to the number of data words of the
data array has been received;
serial/parallel converter means coupled to receive said serial input data
signals from said input means, said serial/parallel converter means
converting said serial input data signals received into a data word if a
first signal is received from said control logic means;
a second FIFO buffer for receiving said data word from said serial/parallel
converter means, and storing said data word in a "first-in, first-out"
sequence;
output means for transferring said data array from said second FIFO buffer
to said computer means if a second video mixer control signal is received.
7. The virtual control apparatus defined by claim 6 wherein said serial
control signals comprise BEGIN signals, INTERVAL signals, and CLOCK
signals, such that each of said BEGIN signals triggers a frame in said
video mixer, and said CLOCK signals synchronize each bit of said data
array.
8. The virtual control apparatus defined by claim 7 wherein said control
logic means generates one of said first signals if one of said INTERVAL
signals is received after one of said INTERVAL signals is synchronously
received with one of said BEGIN signals, and generates one of said second
signals if one of said BEGIN signals is received after one of said
INTERVAL signals is synchronously received with one of said BEGIN signals.
9. The virtual control apparatus defined by claim 8 wherein said input
means receives said serial input data signals from said video mixer
synchronous with the falling edge of said CLOCK signals.
10. A method for performing edit operations on a video mixer, said video
mixer performing edit operations on a plurality of video input sources
coupled to said video mixer pursuant to edit commands received, said video
mixer issuing video mixer control signals indicative of timing of signals
of video input sources coupled to the video mixer, said method comprising
the steps of:
entering through a computing means edit commands to be performed; storing
entered edit commands in an output data array until the commands are to be
executed;
when the entered edit commands are to be performed, transmitting the output
data array to a communication means coupled to the video mixer and
computing means;
receiving said data array from said computing means, said output data array
comprising a plurality of output data words;
receiving video mixer control signals from said video mixer, said control
signals comprising BEGIN signals, INTERVAL signals, and CLOCK signals,
such that each of said BEGIN signals triggers a frame in said video mixer,
and said CLOCK signals synchronize each bit of said output data array;
converting each output data word of the output data array received from
said computing means into serial output data signals, such that one of
said output data words is converted if one of said INTERVAL signals is
received after one of said INTERVAL signals is synchronously received with
one of said BEGIN signals;
transmitting said serial output data signals to said video mixer, such that
said serial output data signals are synchronous with the rising edge of
said CLOCK signals;
receiving in the communication means serial input data signals from said
video mixer, such that said serial input data signals are synchronous with
the falling edge of said CLOCK signals;
converting said input data signals into input data words, such that one of
said input data words is generated when one of said INTERVAL signals is
received after one of said INTERVAL signals is synchronously received with
one of said BEGIN signals;
storing said input data words in an input data array; and
transferring said input data array from said communication means to said
computing means when one of said BEGIN signals is received after one of
said INTERVAL signals is synchronously received with one of said BEGIN
signals;
such that said serial output data signals comprising edit commands are
received within a single transmission to cause said video mixer to invoke
said edit operations during a single frame and said serial output data
signals and serial input data signals can be communicated between the
video mixer and the computing means in a bidirectional manner.
11. The method as set forth in claim 10, wherein said step of transmitting
the output data array to a communication means comprises transmitting the
output data array in parallel, and said step of transferring said input
data array from said communication means to said computer transfers the
input data array in parallel.
12. The method as set forth in claim 11, said serial input data signals
comprising edit commands performed by the video mixer, said method further
comprising the steps of:
said computing means receiving said input data array; and
providing feedback as to the edit commands performed.
13. The method as set forth in claim 11, said serial input data signals
comprising edit commands performed by the video mixer, said method further
comprising the steps of:
said computing means receiving said input data array; and
storing said input data array received; and
transmitting said stored input data array through the communication means
to a second video mixer;
said second video mixer performing the edit operations corresponding to the
edit commands located in the stored input data array.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of video mixers, also known as
video switcher or video edit gear, and particularly to the field of
automated video communication and control between a video mixer and a
computer.
2. Art Background
With the advent of video technology in image recording, it has become more
and more common to use a video mixer for editing video tapes. Video tapes
offer many attractive features. In video recording there are no foot cuts
and no rolls of film to unravel and no footage is lost. A first cut in
video, or any other screening, can be easily saved and reshown at any
time. Complicated video effects can also be accomplished off-line that
would look as real and immediate as they were done on-line. Finally, aside
from any delay due to editorial decisions, videotape editing is
undoubtedly much faster than film editing.
An illustrative example of such a videotape editing system can be found in
the Edit Gear, XV-Z10000, manufactured by the Sony Corporation of Tokyo,
Japan. With a touch of buttons on the control panel, or "switcher head,"
video signals can be combined, mixed, switched, overlapped, inserted,
duplicated, miniaturized, interwoven, compressed, zoomed, scrolled, and
etc., to create a variety of special effects. FIG. 1a illustrates some of
the functions of the XV-Z10000.
As demonstrated in FIG. 1b, the XV-Z10000 consists of two physical units: a
main chassis 300 and a switcher head 110. The main chassis 300 is the
control unit, where input 120 and output 130 video signals are connected
to be processed. The main chassis 300 utilizes a 4-bit microcomputer 101
for processing. The switcher head 110 is the "button panel" which selects
the desired effects such as wipe pattern, luminance, chrominance, and zoom
effect.
Reference is now made to FIG. 2, where the timing scheme for the XV-Z10000
communication protocol is shown. The communication protocol between the
main chassis 300 and the switcher head 110 is known as the "3-point
serial," comprising a BEGIN signal which indicates a frame, an INTERVAL
(INT) signal which indicates a byte, and a clock (SCLK) which represents a
bit. As is shown in FIG. 2, there are currently 8 (bits) cycles of SCLK
for each INT (byte) and 32 INT's for each BEGIN (frame).
It can be appreciated that operating the XV-Z10000 edit gear still requires
manual operation of key buttons, which imposes a limitation as to how many
buttons, or functions, a human operator's hands can manipulate in each
frame. It can also be appreciated that the human operator is required to
be at the "box" to operate because the XV-Z10000 is a stand-alone unit
without any remote accessibility. Further, it can be appreciated that
where an edit decision in one frame is identical to a previous frame, a
human operator still has to re-key in the buttons. Worse yet, to perform
an identical sequence of editing, as may occur if the editing is to be
performed in a different location or at a different time, a human operator
has to re-do the entire sequence with the utmost tedium. Finally, it can
be appreciated that a human video editor still has to be physically at the
"box" to make editing decisions, although it would be more efficient to be
able to make edit decisions at a remote site. In a typical editing studio
with multiple rooms and multiple edit gears, an editor will go from room
to room to perform edits, although a centralized control environment would
be more efficient.
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide the
capability to automate a video mixer with a computer.
It is also an object of the present invention to provide full access to all
the functions of the video mixer in one frame.
It is further an object of the present invention to provide the capability
to store edit sequences and edit decisions to be used at a later time, or
at a different video mixer.
It is another object of the present invention to provide remote access to a
plurality of video mixers in a centralized control environment.
The present invention provides a virtual control apparatus for emulating a
video mixer through a computer. The computer can receive data and command
information from its own command input means, such as a keyboard, a
touch-sensitive screen or a screen controllable by a cursor control
device. The data and command information are mapped into data in format
recognizable by the central processing unit within the computer. The
resulting data and command are either stored in the memory of the computer
or transferred to the video mixer for immediate use. Data transfer between
the video mixer and the computer is implemented through a communication
tool, which establishes the protocol of communication between the computer
and the video mixer. Edit decisions from the video mixer can be
transferred to and saved in the computer memory for subsequent use.
The present invention also provides an automated video communication tool
between the video mixer and the computer for emulating the edit control
panel of the video mixer. In the first mode of transferring data from the
video mixer to the computer, serial data are first converted into parallel
data by a state machine and control logic unit, which detects the
beginning of a new frame. The parallel data are transferred to a FIFO 1
byte at a time. When the end of frame is detected by the state machine and
control unit, all data in the FIFO are outputted to the computer through
an output means.
In the second mode of transferring data from the computer to the video
mixer, parallel input data are entered and stored in a FIFO 1 byte at a
time. Upon an appropriate control signal from the state machine and
control logic unit, parallel data are converted into serial data by a
parallel/serial converter. The serial data are clocked to the output means
of the interface, which ports the serial data to the video mixer on the
rising edge of the clock, while the video mixer's output data are clocked
to the output means of the video mixer on the trailing edge of the clock.
As will be appreciated, the present invention permits edit gear like the
XV-Z10000 to be automated through a computer, such as a personal computer,
which emulates the microcomputer in the edit gear as well as supplements
it with a much greater range of capabilities. As will be apparent from the
following description, the virtual control apparatus and the automated
video communication tool of the present invention permit an editor to
access all the functions of the video mixer in one frame. Also, the
present invention permits a sequence of edit functions to be stored and
downloaded at a later time or to a different video mixer. Furthermore, the
present invention may be configured in a multiple-video mixer system in a
centralized environment whereby the editor can access a multiplicity of
video mixers without physically moving to the video mixer to manually
operate the switcher head.
BRIEF DESCRIPTION OF THE DRAWINGS
The object, features and advantages of the present invention will be
apparent from the following detailed description in which:
FIG. 1a is a pictorial representation of some of the functions of a video
mixer.
FIG. 1b is a block diagram illustrating the edit gear's, XV-Z10000,
environment.
FIG. 1c is a block diagram illustrating the XV-Z10000's environment when
incorporating the presently claimed invention.
FIG. 2 illustrates the "3-point serial" communication protocol for the
XV-Z10000.
FIG. 3a is a block diagram illustrating the automated video communication
tool for XV-Z10000-to-computer transfer.
FIG. 3b is a block diagram illustrating the automated video communication
tool for computer-to-XV-Z10000 transfer.
FIG. 4 illustrates a state diagram for the state machine and control logic
unit within the automated video communication tool.
FIG. 5 illustrates a "virtual control panel" created by using the automated
video communication tool.
FIG. 6 illustrates a virtual control apparatus embodying the presently
claimed invention for automating video editing communication.
DETAILED DESCRIPTION OF THE INVENTION
In the following description, numerous specific details are set forth, such
as specific components, etc., in order to provide a thorough understanding
of the present invention. However, it will be obvious to one skilled in
the art that the present invention may be practiced without the specific
details. In other instances, well-known circuits have not been described
in detail in order not to unnecessarily obscure the present invention.
Particularly, although the following description is based on a video mixer
like Sony's XV-Z10000, it will be appreciated by those skilled in the art
that other video mixer are also available for the intended purposes once
the communication protocol between the interface and the mixer is
specified. For the sake of simplicity, a communication protocol known as
"3-point serial" is described in conjunction with the present invention.
However, it will be apparent to those skilled in the art that other
protocols may be customized to be compatible with the desired edit systems
and the computers.
Reference is now made to FIG. 3(a), where a schematic block diagram of the
presently claimed automated video communication tool ("communication
tool") for a XV-Z1000-to-computer transfer is shown. This computer can be
personal computers of various sizes and capabilities. Control and data
signals from the main chassis of the XV-Z10000 300 enter the communication
tool 10 through an input buffer 310. After the control signals BEGIN and
INT, are detected by the state machine and control logic unit 320, the
data signals are converted into parallel data at a serial/parallel
converter 330. The parallel data are transferred into a "first-in,
first-out" memory (FIFO) 340 upon the detection of another INT control
signal by the state machine and control logic unit 320. The FIFO 340 holds
the data until all the data from within a complete frame are in the FIFO
340, i.e. when the end of a FRAME is detected. Data are transferred from
FIFO 340 to buffer 350. An interrupt to the computer 360 is currently
externally generated by the communication tool 10 through the state
machine and control logic unit 320 for the computer to service at the next
round of communication. When the communication to the computer 360 is
open, data signals in the output buffer 350 are transferred to the
computer 360.
Reference is now made to FIG. 4, where a state diagram for the state
machine and control logic unit is shown. Asynchronously setting the "GO"
bit in the address allows the computer 360 to gain control of the
XV-Z10000 unit 300. As can be seen from the state diagram, the
communication tool of the present invention is initialized by detecting a
BEGIN and a first INT in the incoming signals. Data are transferred out of
the write memory for each INT detected (each INT represents a complete
Byte). When another BEGIN is detected, the data are transferred into a
read memory for the target recipient to read.
Referring back to FIG. 3(b), a schematic block diagram for the presently
claimed communication tool for a computer-to-XV-Z10000 transfer is shown.
Parallel data are first transferred to the input buffer 311 from the
computer 360. When the control signals are sent by the state machine 320,
data are transferred into the FIFO 380. Data in the FIFO 380 are converted
into serial format by the parallel/serial converter 370 upon a control
signal from the state machine and control logic unit and clocked to the
output buffer 351 by the clock unit 390. Serial data are transferred to
the XV-Z10000's main chassis on the rising edge of the clock, while output
data are transferred to the computer 360 on the falling edge of the clock.
FIG. 5 illustrates the data format created by formatting means of the
system using the video communication tool. As can be appreciated, all bits
of the virtual control panel can be set in one frame, which consists of 32
8-bit INT's (Bytes). The user of the system selects via the computer the
editing functions to be executed by the video mixer. The formatting means,
such as the CPU, formats the functions selected into the data format for
transmission via the video communication tool for execution by the mixer
in a single frame. As an illustrative example of the automated video
communication tool, assume that the following edit functions are to be
performed on the switcher head by an operator for one frame:
Zoom up-Mosaic down-Zoom wipe-Scroll I-Mix.
As these functions are executed on the immediate video sources, the
functions are also converted into parallel data format one byte at a time
and transferred to an external computer in binary format according to the
virtual control panel of FIG. 5: (Assuming a "1" indicates that the key is
activated on the 8-by-32 data array.)
______________________________________
Byte 3: 1001 0000 (Zoom and Mosaic down)
Byte 9: 0000 0010 (Mix)
Byte 15: 0000 1010 (Wipe and Scroll I)
Byte 22: 0000 0010 (Mix)
All other bytes of the 32 byte array are inactive ("0").
______________________________________
It can be readily appreciated that the data transferred to the computer can
be stored and retrieved for later use for a different frame or a different
video mixer. As long as the "3-point serial" protocol is established among
the communication tool, the virtual control panel, and the target video
mixer, data can be readily downloaded to a different mixer from the
computer through the communication tool. It will be understood that those
skilled in the art can readily provide necessary softwares interacting
between the computer and the communication tool to create the virtual
control panel. All functions on this virtual control panel can be executed
in one frame, which is less than one second using the current timing
scheme, if all bits in the 32 bytes are set to 1. Without the automated
communication tool and the virtual control panel of the present invention,
the switcher head must execute functions in a sequential method during the
interval of several frames. With the aid of the computer, precise editing
of frames can be achieved by programming the computer to edit a picture on
a frame-by frame or multiple-frame basis. The computer also helps in
developing edit decision lists to conform to a previously drafted edit
decision list precisely, thus achieving effects beyond the capabilities of
the previous manual switcher head control. In addition, edit decisions can
be made first on a computer and then downloaded to the main chassis of a
video mixer, thus achieving higher productivity for any given mixer.
Reference is now made to FIG. 6, where a schematic block diagram of a
virtual control apparatus employing the presently claimed invention is
shown. In one aspect of the operation, edit command inputs are entered
through a command input means 610, which can be either a computer
keyboard, a touch-sensitive screen, or a screen display with a cursor
control device such as a "mouse". The CPU 630, as a formatting means,
formats the data according to the dictates of a software program, which
can be readily designed and implemented by those skilled in the art. After
the data is formatted by the CPU 630, the resulting data can either be
stored in a memory 640 for later use, or outputted to a data input/output
(I/O) means 650 for use by a video mixer 660. The data I/O means 650
transfers the CPU-produced data from the CPU 630 to a video mixer 660,
which manipulates the video input sources 670 to create the desired
effects.
In another aspect of operation, the video mixer 660 operates to manipulate
the video input sources 670. The same data and control signals are
transferred to the CPU 630 through the data I/O means 650, which converts
the data and control signals into proper format for the CPU 630. As
described in the foregoing description, the data I/O means 650 may
comprise an automated video communication tool such that serial data and
control signals are converted into parallel signals for the CPU 630. The
CPU 630 can, in turn, store the data and control signals in its memory 640
for subsequent downloading. As indicated in a schematic block in FIG. 6,
the command input means 610, the CPU 630, and memory 640 can be contained
in a computer unit 600 and the data I/O means 650 can be the interface
board between the computer 600 and the video mixer 660.
Another conceptual representation can be found at FIG. 1c, where
XV-Z10000's control environment embodying the virtual control apparatus of
the present invention is shown. A communication tool 150 interfaces
between a computer 600 and the main chassis 300 of the XV-Z10000. The
switcher head 110 of the XV-Z10000 can control the main chassis 300 to
manipulate the video inputs 120. The main chassis 300 can also be solely
connected to the computer 600 such that the computer can control the main
chassis 300 to manipulate the video inputs 120 as a remote control. As can
be observed in FIG. 1c, the computer 600 can enhance the capability of the
main chassis 300 by replacing the microcomputer 101 of the original
arrangement as in FIG. 1b, as well as the manually-operated switcher head
110.
Furthermore, with reference to FIG. 1c, a switchable connector 199 can be
implemented between the switcher head 110 and the main chassis 300. This
switchable connector can be a plurality of single throw double pole
switches, which can be controlled by the computer 600 or manually
operated, such that one position will allow the commands from the computer
600 to be reflected on the buttons of the switcher head 110 (visual
feedback) and another position of the switchable connector 199 will
disable the switcher head 110 such that the computer 600 communicates with
the main chassis 300 directly with the computer 600 providing visual
feedback of the command inputs. A cable incorporating the switchable
connector 199 has the pinouts illustrated in FIG. 2, where SI and SO
represent "serial-in" and "serial-out," respectively. Additional switches
in the switchable connector can be utilized to direct the data flow
between devices to external leads which may be easily connected to
diagnostic equipment.
Thus, for example, a first switch of the switchable connector 119 can
enable the serial line to switcher head 110 to receive input from the
computer 600 and main chassis 300 such that the switcher head 110 can
provide visible feedback in response to operations performed by the
computer 600 at the main chassis 300. Alternatively, the reverse effect
can be achieved by disabling the serial-out line to the switcher head 110
and enabling the serial-in line to permit user input through the switcher
head 110 and visual feedback at the computer 600. The switchable connector
may also be used to permit the user to switch between input devices when
desirable to achieve different results. For example, a first user may
remotely execute a stored sequence of editing commands through the
computer 600 followed by a second user executing a series of manual edit
commands which the user desires to execute through the switcher head 110.
Alternately a remote user at the computer 600 and a local user at the
switcher head 110 may jointly perform edits by switching between the
switcher head 110 and computer 600.
The present invention further provides a data protection mechanism to avoid
the loss of data or transmission of incorrect data due to switching
between the switcher head 110 and the computer 600. At the end of each
frame, an interrupt is generated by the communication tool 150 to the
computer 600. The computer responds to the interrupt by reading the status
on the state machine in the communication tool 150 and outputting data to
the communication tool (such as editing commands to be performed). Thus
when control of input is changed from the computer to the switcher head,
the computer will complete its output of frame data and wait until control
of input is changed back to the computer. Because the interrupt is not
generated and hence not acted upon until the end of a frame, no data
transmission loss occurs when the switch gives control of data flow from
the computer 600 to the switcher head 110. When control of input is
changed back to the computer, and an interrupt is generated at the end of
a frame, the computer, upon receipt of the interrupt will read the status
and initiate transmission of input data. Currently, the computer 600
echoes back the edit commands as a default mode until modified by the
user. Thus in the present invention, overlap of input data by the switcher
head and computer and data loss are avoided.
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